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Articles 41281 - 41310 of 196042

Full-Text Articles in Engineering

Analysis Of Eye Movements To Cartoon Faces In Videos, Kaustubh Sapru Jan 2022

Analysis Of Eye Movements To Cartoon Faces In Videos, Kaustubh Sapru

Dissertations and Theses

Saccades are rapid eye movements that move our gaze between successive points of fixation. They are indicative of how we direct our attention and therefore play a role in memory and cognition. For static images, it is established that saccades move faster to faces compared to other objects. We hypothesize that the same is true for videos. To test this hypothesis, saccades to faces in motion pictures have been analyzed. The analysis here entails the recording of saccades to two videos followed by a statistical study of saccades going towards faces or going away from faces. What makes this study …


Ai-Driven Automated Medical Imaging Analysis, Jingya Liu Jan 2022

Ai-Driven Automated Medical Imaging Analysis, Jingya Liu

Dissertations and Theses

Medical imaging has been applied widely in many clinical diagnoses to detect and differentiate abnormalities by revealing the internal structure of the human body at normal anatomical and physiological levels. Manual analyzing medical images demands attention and is time-consuming, requiring well-trained expertise. The speed, fatigue, and experience may limit the diagnostic performance, leading to delays and even false diagnoses that significantly impact patient treatment. Therefore, accurate systematic systems based on medical image analysis are crucial for timely clinical diagnosis.

This dissertation focuses on advancing automatic computer-aided diagnosis systems to detect cancer, assisting radiologists with early intervention to improve survival rates. …


Droplets In An Electric Field: Surface Rheology, Coalescence And Rebound, Yu Han Jan 2022

Droplets In An Electric Field: Surface Rheology, Coalescence And Rebound, Yu Han

Dissertations and Theses

Electrocoalescence is the process in which pairs of conducting droplets suspended in a continuous dielectric (nonconducting) liquid phase are drawn together and merge upon the application of an electric field. The electric field polarizes each of the droplets in the field direction. The polarization causes the drops to deform and drives a dipolar attraction which forces them to approach each other and coalesce. Many technologies use electric fields to manipulate fluid dispersions. Electrocoalescence is an essential unit operation for separating water droplets in a crude oil. This water in oil emulsion is stabilized by surfactants, such as asphaltenes, resins and …


A Citizen-Science Approach For Urban Flood Risk Analysis Using Data Science And Machine Learning, Candace Agonafir Jan 2022

A Citizen-Science Approach For Urban Flood Risk Analysis Using Data Science And Machine Learning, Candace Agonafir

Dissertations and Theses

Street flooding is problematic in urban areas, where impervious surfaces, such as concrete, brick, and asphalt prevail, impeding the infiltration of water into the ground. During rain events, water ponds and rise to levels that cause considerable economic damage and physical harm. The main goal of this dissertation is to develop novel approaches toward the comprehension of urban flood risk using data science techniques on crowd-sourced data. This is accomplished by developing a series of data-driven models to identify flood factors of significance and localized areas of flood vulnerability in New York City (NYC). First, the infrastructural (catch basin clogs, …


Development Of Cellulose-Based, Semi-Interpenetrating Network Hydrogels As Tissue-Adhesive, Thermoresponsive, Injectable Implants, Jesse Martin Jan 2022

Development Of Cellulose-Based, Semi-Interpenetrating Network Hydrogels As Tissue-Adhesive, Thermoresponsive, Injectable Implants, Jesse Martin

Dissertations and Theses

Abstract Development of Cellulose-Based, Semi-Interpenetrating Network Hydrogels as Tissue-Adhesive, Thermoresponsive, Injectable Implants

Hydrogels are three-dimensional polymer networks with high water content and tunable mechanical properties, which have been widely investigated as replacements for soft tissues, such as the intervertebral disc (IVD). Various derivatives of the plant polysaccharide, cellulose, have been explored for use as injectable hydrogel implants. Methylcellulose (MC), which exhibits thermogelation at temperatures above 32°C, and relatively hydrophilic carboxymethyl-cellulose (CMC), are versatile cellulosic polymers that have shown promise as base materials for such applications. In prior work, functionalization with methacrylate groups allowed for the formation of stable, covalently crosslinked …


Towards Simulation Of Complex Ocean Flows: Analysis And Algorithm For Computation Of Coupled Partial Differential Equations, Wenbin Dong Jan 2022

Towards Simulation Of Complex Ocean Flows: Analysis And Algorithm For Computation Of Coupled Partial Differential Equations, Wenbin Dong

Dissertations and Theses

The hybrid CFD models which usually consist of 2 sub-models, develop our capability to simulate many emerging problems with multiphysics and multiscale flows, especially for the coastal ocean flows interacted with local phenomena of interest. For most cases, the sub-models are connected with direct interpolation which is easy and workable. It becomes urgently needed to investigate the inner mechanism of such model integration as this simple method does not work well if the two sub-models are different in governing equations, numerical methods, and computational grids. Also, it can not treat complex flow structures as well as the balance in mass …


Low-Intensity Ultrasonic Neuromodulation Of The Rat Hippocampus, Duc Nguyen Jan 2022

Low-Intensity Ultrasonic Neuromodulation Of The Rat Hippocampus, Duc Nguyen

Dissertations and Theses

Techniques to non-invasively modulate brain activity are important for mapping human brain circuits, and also for the treatment of a host of neurological and psychiatric disorders marked by aberrant brain activity. Though a wide range of techniques for non-invasive neuromodulation have been proposed, the conventional approaches suffer from significant limitations. Most notably, focal stimulation of deep brain regions is presently only possible with invasive optogenetic and chemogenetic approaches that require craniotomies and genetic access to the brain.

Transcranial focused ultrasound stimulation (tFUS) possesses many of the characteristics desirable from a neuromodulation approach: non-invasiveness, a spatial resolution in the order of …


Investigation Of Reactions Occurring In Municipal Solid Waste Residues, Tasnuva T. Moutushi Jan 2022

Investigation Of Reactions Occurring In Municipal Solid Waste Residues, Tasnuva T. Moutushi

Dissertations and Theses

Each year more than 290 million tons of municipal solid waste (MSW) is generated in the U.S. Understanding the reactions occurring in waste during disposal, transport, and storage is important to move towards an integrated waste management strategy. Recently some landfills in the U.S. have been reported to exceed the regulatory temperature range, causing numerous regulatory challenges. The reason for this phenomenon is still unidentified. In addition, the co-disposal of the MSW ash in landfills lead to various reactions which can impact the landfill environment. Understanding the reactions occurring in the MSW and in ash is essential to minimize and …


Investigation Of Recyclable And Renewable Crude Oil From Biomass And Plastics, Golam Chowdhury Jan 2022

Investigation Of Recyclable And Renewable Crude Oil From Biomass And Plastics, Golam Chowdhury

Dissertations and Theses

In the present world, the nonrenewable source of petroleum crude oil is suspected to cause irreversible climate impacts. So, refinery companies are looking for renewable and recyclable crude oil (RCOs). Biomass and Plastics are a great sources of RCOs. The goal of this work is to design, build and operate a pyrolysis reactor which is capable of converting different solid feedstock derived from waste to pyrolysis oil. The oils are characterized by GC-MS and sent to BASF Corporation in Iselin, NJ for catalytic upgrading potential. In this study, the feedstock ranged from virgin plastic resins (LDPE, HDPE, PS, PP), recycled …


Investigations Of The Therman Treatment Of Sodium Thiosulfate In Gas Streams For The Removal Of I2, Anjeza Arapi Jan 2022

Investigations Of The Therman Treatment Of Sodium Thiosulfate In Gas Streams For The Removal Of I2, Anjeza Arapi

Dissertations and Theses

The aim of this work was to study the performance of sodium thiosulfate in several systems. Sodium thiosulfate decomposition and SO2 conversion were analyzed using thermogravimetric analysis combined with chromatographic techniques. Thermogravimetric analysis (TGA) measurements determined the decomposition of the acidification reaction of 30% sodium thiosulfate solution in a 14% carbon dioxide (CO2) atmosphere and 1% hydrochloric acid (HCl) solution in the temperature regime of 300 - 750 K. Sodium thiosulfate and sulfur dioxide (SO2) are considered effective methods for removing iodine (I2) from air and flue-gas streams respectively. In acid containing gas-streams where the SO2 content is determined by …


Achievements And Prospects Of Functional Pavement: Materials And Structures, Jian-Long Zheng, Zhanping You, Xueyan Liu Jan 2022

Achievements And Prospects Of Functional Pavement: Materials And Structures, Jian-Long Zheng, Zhanping You, Xueyan Liu

Michigan Tech Publications, Part 1

No abstract provided.


Shear Thickening In Dense Bidisperse Suspensions By Dynamic Simulation, Nelya Malbranche Jan 2022

Shear Thickening In Dense Bidisperse Suspensions By Dynamic Simulation, Nelya Malbranche

Dissertations and Theses

Shear thickening, which corresponds to an increase of viscosity with shear rate, is ubiquitously observed in many concentrated suspensions and, as such, has implications for many industrial materials and geological phenomena. Controlling shear thickening is of significant importance, and many studies have been devoted to it. Recent works link shear thickening to the shear-induced transition from a lubricated particle interaction at low shear stress to a predominantly frictional interaction at high stress. In this dissertation, we investigate bidispersity and focus on mechanisms contributing to the viscosity evolution in rate-dependent suspensions, something that has not been addressed before. We perform detailed …


Exosome- And Microrna-Based Therapeutic Approach For Tendinopathy, Angela Wang Ilaltdinov Jan 2022

Exosome- And Microrna-Based Therapeutic Approach For Tendinopathy, Angela Wang Ilaltdinov

Dissertations and Theses

Tendinopathy, characterized by degeneration and chronic inflammation, is a significant clinical burden. Current treatments focus on symptom management but do not sufficiently address its underlying pathology; however, stem cell-based approaches aimed at repairing diseased tissues may overcome this limitation. Therapeutic effects of stem cells may be due in part to paracrine actions, including some mediated by exosomes – extracellular vesicles secreted by cells that play a role in cell communication. MicroRNA (miRNA), small non-coding RNA carried by exosomes, are likely responsible for many exosome effects. Exosomes and miRNA therapies show promise in treating diseases such as cancer and arthritis, but …


Light Trapping Transparent Electrodes, Mengdi Sun Jan 2022

Light Trapping Transparent Electrodes, Mengdi Sun

Electronic Theses and Dissertations, 2020-2023

Transparent electrodes represent a critical component in a wide range of optoelectronic devices such as high-speed photodetectors and solar cells. Fundamentally, the presence of any conductive structures in the optical path leads to dissipation and reflection, which adversely affects device performance. Many different approaches have been attempted to minimize such shadowing losses, including the use of transparent conductive oxides (TCOs), metallic nanowire mesh grids, graphene-based contacts, and high-aspect ratio metallic wire arrays. In this dissertation I discuss a conceptually different approach to achieve transparent electrodes, which involves recapturing photons initially reflected by highly conductive electrode lines. To achieve this, light-redirecting …


Investigations Of The Low Temperature Combustion Regions And Emissions Characteristics Of Aerospace F24 In A Constant Volume Combustion Chamber And A Common Rail Direct Injection Ci Engine, Richard C. Smith Iii Jan 2022

Investigations Of The Low Temperature Combustion Regions And Emissions Characteristics Of Aerospace F24 In A Constant Volume Combustion Chamber And A Common Rail Direct Injection Ci Engine, Richard C. Smith Iii

College of Graduate Studies: Theses & Dissertations

A study was conducted to investigate the low temperature combustion (LTC) regions of aerospace F24 and ULSD in the static setting of a CVCC and the dynamic setting of a CRDI research engine. This research is conducted to reduce in-cylinder emissions by understanding and implementing a technique to achieve an extended LTC. Emissions data for this study were collected during the operation of the CRDI research engine with a MKS 2030 FTIR and an AVL Microsoot 483. The parameters researched within the static setting of the CVCC included the determinations of the cool flames and NTC regions within the LTHR …


Analysis Of Spatial Discrepancies Between 76-Foot Close Range Photogrammetric And Terrestrial-Lidar Models, Abdoul K. Ouangre Jan 2022

Analysis Of Spatial Discrepancies Between 76-Foot Close Range Photogrammetric And Terrestrial-Lidar Models, Abdoul K. Ouangre

College of Graduate Studies: Theses & Dissertations

This study presents an analysis of the accuracy of a 3D model generated by two different methods. In the first method, the 3D model is generated via Laser Scanning. In the second method, the 3D model is generated via Close-range Photogrammetry from a drone flying at 76 feet above the ground. Photogrammetry is a photo-based technique that uses images to generate 3D models of objects where distances could be extracted from. Close-range photogrammetry is the approach of generating a 3D model from a camera placed anywhere between 1 foot and 1000 feet relative to the object. Terrestrial LiDAR is the …


Analysis Of Bio-Alcohols With Mie-Scattering And Ltc For Lowered Emissions In Pcci, Cesar E. Carapia Jan 2022

Analysis Of Bio-Alcohols With Mie-Scattering And Ltc For Lowered Emissions In Pcci, Cesar E. Carapia

College of Graduate Studies: Theses & Dissertations

An investigation was conducted on the optimal engine parameters for facilitating lower NOX and soot emissions of PCCI combustion with either ethanol or n-butanol. The PFI fuels selected were tested at loads of 3, 4, and 5 Bar IMEP for a total of 28 total combustion tests with variations made to the EGR% and boost pressure for each test in order to find the optimal emissions strategy. A Mie-scattering spray fuel analysis was also conducted on the three fuels to gain insight on their influence on combustion/emissions characteristics. It was found that ethanol had a greater average Sauter Mean Diameter …


Effects Of Titanium And Cerium Addition On Grain Size And Mechanical Properties Of Ductile Iron Castings, Shelton F. Fowler Iv Jan 2022

Effects Of Titanium And Cerium Addition On Grain Size And Mechanical Properties Of Ductile Iron Castings, Shelton F. Fowler Iv

College of Graduate Studies: Theses & Dissertations

According to the Hall-Petch equation, the refinement of grains in metals increases the yield strength of the material. Austenite grain size influences the fineness of microstructural constituents in the ferrous alloys. It is well studied that cerium and titanium refine the austenite in steels and some gray irons, but no studies have been done to systematically explore the effects of cerium and titanium additions on austenite in ductile iron. This study sought to determine the effects of selected levels of these elements on the grain size within ductile iron. A hypoeutectic iron was chosen for testing as the proeutectic phase …


The Implementation Of Advanced Digitalization In The Oil And Gas Industry, Ensieh Rezafar Jan 2022

The Implementation Of Advanced Digitalization In The Oil And Gas Industry, Ensieh Rezafar

Walden Dissertations and Doctoral Studies

AbstractThe immature advanced digitalization in the oil and gas industry can limit access to the potential value of mature progressive digitalization. Oil and gas leaders must expedite the implementation of advanced digitalization to increase organizational proficiencies and reduce costs and losses. Grounded in Pettigrew and Whipp’s dimensions of strategic change theory, the purpose of this qualitative multiple case study was to explore strategies some leaders in the oil and gas industry used to implement advanced digitalization. The participants were seven leaders in two oil service companies in North America involved in the successful implementation of progressive digitalization. Data were collected …


The Relationship Between First Case On-Time Starts, Turnover Times, And Operating Room Productivity, Rhafia Bucoy Jan 2022

The Relationship Between First Case On-Time Starts, Turnover Times, And Operating Room Productivity, Rhafia Bucoy

Walden Dissertations and Doctoral Studies

Operating room (OR) managers struggle to manage day-to-day surgical operations while meeting and exceeding organizational productivity amid the COVID-19 pandemic. The deferral of surgeries contributes to millions of backlogs of surgical case volume and unintended negative consequences. Grounded in the proposition that first-case on-time starts (FCOTS) and turnover time (TOT) are correlates of OR productivity, the purpose of this quantitative correlational study was to examine the relationship between FCOTS, TOT, and OR productivity. Archival data from 136 electronic surgical records were collected from two free-standing ambulatory surgery centers and analyzed using multiple regression. The results of the one-service, eye-specialized, ambulatory …


Mixed-Integer Programming Methods For Modeling And Optimization Of Cascading Processes In Complex Networked Systems, Cheng-Lung Chen Jan 2022

Mixed-Integer Programming Methods For Modeling And Optimization Of Cascading Processes In Complex Networked Systems, Cheng-Lung Chen

Electronic Theses and Dissertations, 2020-2023

Dynamics and growth of many natural and man-made systems can be represented by large-scale complex networks. Entity interactions and community interconnections within complex networks increase the level of difficulty for the investigation on structural network properties such as robustness, vulnerability and resilience. In this dissertation, we develop methodologies based on mixed-integer programming techniques to solve challenging optimization problems that model cascading processes in complex networked systems. In particular, we seek to provide decision making recommendations for problems related to different types of cascading processes in networks commonly considered in a variety of applications: interdependent infrastructure networks and social networks. In …


Non-Invasive Detection Of Elevated Intracranial Pressure Using Spontaneous Tympanic Membrane Pulsation, Rajkumar Dhar Jan 2022

Non-Invasive Detection Of Elevated Intracranial Pressure Using Spontaneous Tympanic Membrane Pulsation, Rajkumar Dhar

Electronic Theses and Dissertations, 2020-2023

Monitoring intracranial pressure (ICP) is a standard diagnostic tool for various neurological conditions such as head injury, ruptured aneurysms, intracerebral and intracranial hemorrhage, and hydrocephalus. Currently, ICP monitoring relies on invasive pressure measurements. These include intraventricular catheter, subdural screw, epidural sensor, and lumbar puncture. Invasive methods pose the risk of infection and hemorrhage, are expensive, and require special clinical skills. A noninvasive method that is reliable, simple to use, low-cost, and provides easily interpretable results can help avoid the complications associated with the invasive methods. This study proposes a novel method for noninvasive ICP monitoring using tympanic membrane pulsation (TMp). …


A Measurement System For Detection Of Intestinal Motility In Neonates By Monitoring Slow Wave Activity, Garett Goodale Jan 2022

A Measurement System For Detection Of Intestinal Motility In Neonates By Monitoring Slow Wave Activity, Garett Goodale

Electronic Theses and Dissertations, 2020-2023

Similar to how electrocardiographic waves are the pace making signals of the heart, slow waves are the pace making signals of the intestines. Slow waves are electrical signals in the intestines that determine the speed at which food can move through the intestine ensuring proper digestion and uptake of nutrients. It has been shown that slow waves can be measured in adults using non-invasive, surface electrodes. However, no study has investigated the measurements of slow waves in neonates, specifically pre-term neonates. Around 7% of pre-term neonates suffer from necrotizing enterocolitis (NEC) which is a condition that causes damage to the …


Assessing Patient Safety Culture In United States' Hospitals, Abdulmajeed Azyabi Jan 2022

Assessing Patient Safety Culture In United States' Hospitals, Abdulmajeed Azyabi

Electronic Theses and Dissertations, 2020-2023

Patient safety is founded on continuous learning because there is an urgent need to report and learn from errors, accidents, near misses, and adverse events. The traditional approach to patient safety, based on forming mortality committees and investigating accidents, will no longer be effective. Frameworks, surveys, and assessment tools have been developed over the last decade to assist organizations in measuring and understanding their culture. This a retrospective cross-sectional study included 67,010 respondents from Agency for Health care Research and Quality (AHRQ) 2018 comparative database was analyzed using partial least squares structural equation modeling (PLS-SEM). This research explored whether the …


In Situ Transmission Electron Microscopy And Ab Initio Study Of The Electrochemomechanical Effect Of Lithium Penetration In Electrolytes For All-Solid-State Batteries, Megan Diaz Jan 2022

In Situ Transmission Electron Microscopy And Ab Initio Study Of The Electrochemomechanical Effect Of Lithium Penetration In Electrolytes For All-Solid-State Batteries, Megan Diaz

Electronic Theses and Dissertations, 2020-2023

Although the past twenty years have seen dramatic advancement in lithium-ion batteries (LIBs), these batteries are nearing their theoretical limit. Next generation energy storage technologies must therefore be developed to meet the ever-increasing demands for batteries with higher capacity, longer cycle lifetime, and increased safety. All-solid-state lithium battery (ASSLIB) technology is one of the promising candidates. It is equipped with a solid-state electrolyte (SSE) replacing the flammable organic liquid electrolyte used in current LIBs. The SSE's high modulus is expected to prevent lithium dendrites and enables the use of a lithium metal anode to contribute to its high capacity without …


Modeling And Experimentation Of Buckling Of Composite Deployable Booms Under Bending, Christopher D. Rehberg Jan 2022

Modeling And Experimentation Of Buckling Of Composite Deployable Booms Under Bending, Christopher D. Rehberg

Electronic Theses and Dissertations, 2020-2023

This thesis presents experimental and finite element analysis results of eccentrically loaded carbon-fiber composite booms that can deploy solar sails. Using the collapsible tubular mast design along with the geometry from the upcoming Advance Composite Solar Sail System mission, short composite booms segments were manufactured for testing. New clamps were also designed to allow a column bending test to achieve eccentric loading. As buckling through eccentric loading has not previously seen much research, the geometry and composite layups were simplified to allow for ease of manufacturing and verification. The work presented here shows that a finite element simulation, using a …


Energy Based Diagnostics Of Cfd: Revealing New Insights To Complex Aerodynamics, George Loubimov Jan 2022

Energy Based Diagnostics Of Cfd: Revealing New Insights To Complex Aerodynamics, George Loubimov

Electronic Theses and Dissertations, 2020-2023

This thesis documents a new approach to assess the aerodynamics of complex fluid dynamic systems using modern assessment methods associated with computational fluid dynamics (CFD). The method is developed to extract novel and additional insight in the context of a higher-fidelity modeling tool. Although the methods are based on classical control volume techniques balancing fluid momentum and energy, the approach uses the detailed data provided by CFD to expand on it. Classical methods typically use a fixing control volume defined at simple control surfaces, whereas this assessment method utilizes CFD to provide complex integrals on the control surfaces and uses …


The Proof Of Concept Of The Hurricane Imaging Radiometer: Hurricane Wind Speed And Rain Rate Retrievals, Jonathan Coto Jan 2022

The Proof Of Concept Of The Hurricane Imaging Radiometer: Hurricane Wind Speed And Rain Rate Retrievals, Jonathan Coto

Electronic Theses and Dissertations, 2020-2023

This dissertation presents the proof of concept for the Hurricane Imaging Radiometer (HIRAD), where remote sensing retrievals of the 2-dimensional wind and rain fields for several hurricanes are validated with independent measurements. A significant contribution of this dissertation is the development of a novel statistical calibration technique, whereby the HIRAD instrument is radiometrically calibrated, using modeled brightness temperatures (Tb) generated using a priori hurricane wind and rain fields that are statistically representative of the actual hurricane conditions at the time of the HIRAD brightness temperature measurements. For this calibration technique, the probability distribution function of the measured HIRAD Tb's is …


Air Force Pilot's Recognition About The Effectiveness Of Active Noise Cancellation On Hearing Health, Performance, And Aviation Safety, Kyungtaek Hwang Jan 2022

Air Force Pilot's Recognition About The Effectiveness Of Active Noise Cancellation On Hearing Health, Performance, And Aviation Safety, Kyungtaek Hwang

Electronic Theses and Dissertations, 2020-2023

The purpose of this thesis is to suggest the application of Active Noise Cancellation in Air Force pilot headset and helmet not only to reduce noise-induced hearing damage, but also to enhance pilot performance and aviation safety. Despite the recent advances of sound treatment technology, the interior sounds of a military aircraft exceed the damage risk criterion of 8 hrs/day exposure. Air Force pilots are flying under the extreme condition where noise is severe and prevalent. The exposure to noise can lead to permanent hearing loss, stress and fatigue, unintelligible communication, and deterioration of speech perception and recall. With all …


Mixed-Criticality System Design For Real-Time Scheduling And Routing Upon Platforms With Uncertainties, Sudharsan Vaidhun Bhaskar Jan 2022

Mixed-Criticality System Design For Real-Time Scheduling And Routing Upon Platforms With Uncertainties, Sudharsan Vaidhun Bhaskar

Electronic Theses and Dissertations, 2020-2023

Unlike typical computing systems, applications in real-time systems require strict timing guarantees. In the pursuit of providing guarantees, the complex dynamic behaviors of these systems are simplified using models to keep the analysis tractable. In order to guarantee safety, such models often involve pessimistic assumptions. While the amount of pessimism was reasonable for simple computing platforms, for modern platforms the pessimism involves ignoring features that improve performance such as cache usage, instruction pipelines, and more. In this work, we explore routing and scheduling problems in real-time systems, where the uncertainties in the operation are carefully accounted for by complex models …